The cloud giant has set goals of being powered by 50% renewable energy by the end of this year, but Greenpeace says that an increase in data centre construction in Virginia will play a role in making goals like that, and the 100% goal, elusive.

The problem is that Virginia relies almost solely upon electricity that is created from coal and nuclear power plants.

The figure, which is adjusted for various factors, is down from 23% in 2015.

The report said that the near doubling of the data centre capacity in Virginia, “far outstripped the addition of renewable energy supply.”

Amazon has taken steps to throw its weight behind renewable energy policies and has set about building both solar and wind farms.

The leading cloud giants such as AWS, Microsoft and Google have all made moves to become more efficient in their data centre energy use and this has helped their US data centres to use near constant amounts of energy over the past decade, according to a 2016 report by the Berkeley Lab.

That is despite the significant growth in the cloud industry over that time frame. However, Greenpeace believes that the continued growth of cloud, combined with the popularity of video streaming and other elements, could counteract some of the efficiency gains being made.

In 2016, around 45% of energy for AWS came from renewable sources and Amazon has commissioned 10 renewable energy projects such as solar and wind farms to help power its data centres in areas such as Ohio and Northern Virginia, four of which are now online.

The company is one of many tech firms that also filed an amicus brief that backed the US Environmental Protection Agency’s Clean Power Plan, which aims to curb power plant emissions.

Despite this, Greenpeace points to 14 AWS facilities in Virginia which it says are about 3% “clean”, with coal, nuclear and natural gas each accounting for around a third of the power supply.

Oregon meanwhile has a much greener footprint, 85% of it is powered by hydroelectric or other renewable.

On the whole, Greenpeace says that on average 30% of the company’s energy needs are met by coal, nuclear 26% and natural gas 24%.

The report said estimates that the energy needs of AWS are around 17% clean energy, below the 32% for Microsoft and 56% for Google.

One of the biggest problems for Amazon and Greenpeace, is a lack of transparency, with the environmental group calling Amazon “one of the single biggest obstacles to sector transparency,” due to it not disclosing “basic details” about its energy footprint.